Reaktion #64427

Reaktionsgleichung

1-bromo-5-benzyloxy pentane

t-butyl lithium

3-bromo-phenol

n-pentyl ether

3-(benzyloxypentyl)-phenol

n-pentyl ether

→

3-(5-hydroxypentyl)-phenol

n-pentyl ether

Lösungsmittel

ethanol

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGis then stirred an additional 24 hours
2. 2
   Sonstigebefore being quenched with silica gel
3. 3
   SonstigeAfter removing the solvent
4. 4
   Sonstigethe mixture is chromatographed over silica gel (1:1 hexane:ether)
5. 5
   Sonstigeto yield a crude mixture
6. 6
   FiltrationAfter filtering through celite
7. 7
   Einengenconcentrating

Vorschrift

At a temperature of -78° C., 19.4 ml of t-butyl lithium (1.7M) is added to 4.0 gm of the above 3-bromo-phenol, n-pentyl ether in 50 mls tetrahydrofuran; and to this is added 3.3 ml of a freshly prepared solution of Li2CuCl3 (0.10M/THF). The mixture is stirred for 10 minutes, and then 4.35 grams of the 1-bromo-5-benzyloxy pentane are added. The reaction is allowed to warm slowly to ambient temperature over 12 hours and is then stirred an additional 24 hours before being quenched with silica gel. After removing the solvent, the mixture is chromatographed over silica gel (1:1 hexane:ether) to yield a crude mixture containing 3-(benzyloxypentyl)-phenol, n-pentyl ether. A solution of 6.0 gm of this crude mixture in ethanol is hydrogenated over 5% Pd on carbon for 5 hours. After filtering through celite and concentrating, pure 3-(5-hydroxypentyl)-phenol, n-pentyl ether is obtained as a clear oil by HPLC chromatography.

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